El Nino events

Tarras-Wahlberg NH, Lane SN (2003) Suspended sediment yield and metal contamination in a river catchment affected by El Nino events and gold mining activities the Puyango river basin, southern Ecuador. Hydrol Process 17 3101... 

Abrupt temperature changes are easier to appreciate than long-term changes. El Nino events, which are the best examples of the first type, occur in Indonesian forests in synergisms with threatening by human activities (Curran 1999). The same probably occurs on coral reefe too, where El Nino warming causes the death of seaweeds and invertebrates, in particular corals, which are extremely sensitive to temperature variations. 

Considerable progress in modeling the interactive atmosphere-ocean system has made it possible to successfully predict seasonal and interannual variability and, in particular, El Nino events. The sufficiently adequate consideration of land surface processes ensured a substantial increase in hydrological prediction reliability (river run-off included). 

Consideration of the impact of low-frequency fluctuations of climate on Caspian Sea level showed that the long-term variability of the level is connected mainly with SST anomalies in the eastern part of the tropical Pacific Ocean. It turns out that positive SST anomalies correlate with the growing rain rate in the Volga River watershed basin and vice versa. The main reason for variations in Caspian Sea level is the long-term dynamics of El Nino events, which should be considered as chaotic. 

In order to reveal the response of the Black Sea SST to the ENSO and NAO, we compared the years of the extreme seasonal SST values observed (Figs. 3, 4) with the phases of the oscillations cited and the character of their decadal variability. The periods of the El Nino events are indicated in Figs. 2,3, and 5. The character of the changes in the ENSO and NAO indices in 1950-2002 may be judged from Fig. 6 (the negative values of the ENSO index correspond to the El Nino events). 

As follows from Fig. 6, in the period 1954-2002, 12 El Nino events occurred. Of them, the events of 1982-1983 and 1997-1998 were the most intensive and that of 1990-1995 was the most prolonged. Since the time de-... 

One can see that, in the period 1954-2002, most of the strongly pronounced winter SST anomalies (11 of 16) occurred either during the El Nino events or in the years immediately after them. Three anomalies (1962, 1976, and 2001) might be related to the La Nina events. The anomalies of 1961 and 1985, in the years with low values of the ENSO index, can hardly be referred to a certain phase of this atmospheric oscillation. Five of the 11 winters related to the El Nino events were cold and six others were warm. During the 1990-1995 El Nino, both cold (in 1992 and 1993), and warm (in 1995) winters were observed. It should be noted that an extreme value of the winter SST is not directly related to the intensity of El Nino. For example, one of the highest values of the winter SST was related to the relatively weak El Nino event of... 

The greater part of the summer SST anomalies (maximums in 1966, 1972, 1994, and 2002 and minimums in 1982, 1984,1993, and 1997) corresponded to the years of the El Nino events. The warm summer of 1999 was probably also related to El Nino. All the cold SST anomalies in spring (Fig. 3b) and most of them in autumn (Fig. 3d) corresponded to the El Nino periods, and most of the temperature maximums in these transition seasons were likely to be also associated with the events. 

It is probable that the cold summer of 1982 in the Black Sea as well as in the Mediterranean Sea [30] and in the northeastern Atlantic [31] was caused by the aerosols from the El Chichon (Mexican volcano) eruption in April 1982 [18]. Similarly, the eruption of Mount Pinatubo (Philippines volcano) in June 1991, whose after-effects were traced in the atmosphere of the Northern Hemisphere up to 1995 (as follows from the modeling results), might also make its contribution to the anomalously cold winter and summer of 1993 [32]. It is interesting that both of these volcanic eruptions coincided with the El Nino events of 1982-1983 and 1990-1995. 

Dettinger et al. 2000, Marengo et al. 2001d). These associations are more apparent during the period since the middle 1970s when there were more moderate to strong El Nino events. The variability of NAR and SAR reflects the ENSO effects at interannual scales, and on decadal scales with less rain in... 

Decadal Changes in political climate, household labor availability by life cycle Recruitment of economic species, El Nino events... 

Kennedy J. and Brassell S. C. (1992) Molecular records of twentieth century El Nino events in laminated sediments from Santa Barbara basin. Nature 357, 62—64. 

Many complicated issues remain at the forefront of meteorology, including air pollution, global warming, El Nino events, climate change, ozone hole, and acid rain issues. 

Frappier, A., Sahagian, D., Gonzalez, L.A. Carpenter, S.J. (2002) El Nino events recorded by stalagmite carbon isotopes. Science 298, 565. 

Fig. 7.8 Fossil-fuel emissions and the rate of increase of C02 concentrations in the atmosphere. Vertical arrows define El Nino events (see text for discussion). Data from IPCC (2001). With permission of the Intergovernmental Panel on Climate Change.

ENSO events are characterized by reversals of the atmospheric pressure systems in the south and central Pacific and switching of the sources of the intensely upwelled water masses along the southeastern Pacific continental margin. An El Nino event results in warmer surface waters, greater stratification and reduced upwelling of nutrients in the central and eastern equatorial Pacific, reducing primary productivity. While reduced equatorial-subequatorial productivity during El Nino is observed in the central eastern Pacific in all studied events (Barber Chavez, 1983 Barber etal., 1996 Strutton Chavez, 2000), the effects of ENSO events on POC flux to the seafloor are not clear. 

Fig. 10. Variations in (a) sea-surface temperature in the Rabaul region and (b) Sr/Ca ratio of a Rabaul coral. Shaded vertical bars denote ENSO warm phase (El Nino) events. Data from Rayner et al. (2003) and C inn et al. (2006).

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